JP2656171B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine.

[0002]

2. Description of the Related Art Generally, an exposing apparatus of a copying machine includes an optical traveling body having an optical system for exposing and scanning an original image, and a traveling body for reciprocatingly driving the optical traveling body at a speed corresponding to a copy magnification. And a driving device. Then, the original image is exposed and scanned during the forward movement of the optical system traveling body,
An original image is projected on the photosensitive drum.

[0003] The moving speed of the optical system traveling body is set to be equal to the moving speed of the photosensitive drum when the copy magnification is the same, and faster than the moving speed of the photosensitive drum when the copy magnification is the reduction magnification. Is set to
Therefore, the time from when the optical system traveling body is at the traveling start position to when the speed of the optical system traveling body reaches the set speed when the copy magnification is the reduction magnification is equal to the time when the copy magnification is the same magnification. It takes longer than the time from when the optical system traveling body is at the traveling start position until the speed of the optical system traveling body reaches the set speed.

Further, when the copying magnification is the reduction magnification, the traveling distance from the traveling start position of the optical system traveling body to the speed at which the optical system traveling body reaches the set speed is determined when the copying magnification is equal. It takes longer than the distance from the traveling start position of the optical system traveling body until the speed of the optical system traveling body reaches the set speed.

Conventionally, the distance in the forward running section from the running start position of the optical system traveling body to the document scanning start point is uniform with respect to the reduction magnification at which the acceleration distance of the optical traveling body is longest regardless of the copying magnification. Was set to

[0006]

However, when the copy magnification is the same magnification or the enlargement magnification, the distance of the forward running section from the traveling start position of the optical system traveling body to the original scanning start point becomes smaller as the reduction magnification. Long distances are not required. For this reason, in the conventional apparatus, when the copy magnification is the same magnification or the enlargement magnification, there is a problem that useless time is consumed for the pre-scan and the copy speed is slow. In particular, when the copy magnification is the same magnification or the enlargement magnification and continuous copying is performed, there is a problem that a waste time is long.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus capable of reducing a copying time in a continuous copy mode.

[0008]

SUMMARY OF THE INVENTION An image forming apparatus according to the present invention reciprocates an optical system traveling body having an optical system for exposing and scanning an original image at a speed corresponding to a copy magnification. Image forming apparatus provided with a driving device for driving the vehicle at a magnification greater than a predetermined first magnification.
When making a continuous copy, the second and subsequent optical system
Running when the running start position is copied at the above first magnification
From the line start position, closer to the document scanning start position,
It is characterized by controlling the traveling body drive device.

[0009]

[Action] Continuous copying is performed at a magnification larger than a predetermined first magnification.
When performing, the starting position of the second and subsequent optical system traveling bodies
The starting position when copying at the first magnification.
Thus, the traveling body driving device is controlled so as to approach the document scanning start position . For this reason, it is larger than the predetermined first magnification.
When performing continuous copying at an appropriate magnification, the copying time can be reduced.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a main part of an electrophotographic copying machine.

A contact glass 2 on which an original to be copied is placed is provided on an upper portion of a copying machine main body 1 of the copying machine.

A photosensitive drum 3 is arranged in the center of the copying machine main body 1. Around the photoconductor drum 3, a charger 4 for charging the photoconductor layer on the surface of the photoconductor drum 3 along a rotation direction (a direction indicated by an arrow A in FIG. 1), and a static electricity formed on the photoconductor layer. A developing device 5 that makes the electro-latent image noticeable as a toner image; a registration roller 6 that conveys the recording paper to the photosensitive drum 3; and a transfer discharger 7 that transfers the toner image formed on the photosensitive layer onto the recording paper. A separation discharger 8 for separating recording paper from the photosensitive drum 3 and a cleaning device 9 for removing toner remaining on the photosensitive drum 3 after transfer are arranged. The registration roller 6 is connected to a drive source (not shown) via a registration clutch 54 (see FIG. 4).

An exposure lamp 11 and a reflection plate 12 for exposing and scanning an image of a document placed on a contact glass 2 and a first mirror for reflecting light reflected from the document are provided in an upper portion of the body 1 of the copying machine. 13 and the first optical system traveling body 1
0 is reciprocally movable in the directions indicated by arrows F and R. Arrow F indicates the forward movement direction, and arrow R indicates the backward movement direction.

The first optical system traveling body 10 is always located at a first traveling start position P1 (see FIG. 5) shown in FIGS. 1 and 2. As shown in FIG. 2, a detection plate 14 is provided on the first optical system traveling body 10 so as to protrude downward. On the copying machine main body 1 side, a first optical system traveling body 10 is
A position detector 15 is provided for detecting the detection plate 14 when returning to the second traveling start position P2 (see FIG. 5) ahead of the traveling start position P1.

Further, the first part in the copying machine main body 1 has a first
The second optical system traveling body 2 including the second and third mirrors 21 and 22 for guiding the light reflected by the mirror 13 to a fourth reflection mirror 31 that projects the light on the photosensitive layer of the photosensitive drum 3
0 is reciprocally movable in the directions indicated by arrows F and R.

FIG. 3 shows the first optical system traveling body 10 and the second optical system traveling body 10.
The drive mechanism of the optical system traveling body 20 is shown.

First, second, and third pulleys 41, 42, and 43 are rotatably supported by the copying machine body 1. Further, a drive motor 40 is supported by the copying machine body 1, and
A fourth pulley 44 is connected to an output shaft of the drive motor 40. A floating pulley 45 is supported by the copying machine body 1 so as to be movable in the directions of arrows F and R. A wire 46 is hung on these pulleys 41 to 45.

The first optical system traveling body 10 is connected to a wire 46 by a locking member 47. Second optical system traveling body 20
Is connected to the floating pulley 45. When the drive motor 40 rotates in the forward or reverse direction, the first optical system traveling body 10 and the second optical system traveling body 20 move in the direction of the arrow F or R. At this time, the second optical system traveling body 20
Moves at a speed that is half the speed of the first optical system traveling body 10 and is a half of the moving distance of the first optical system traveling body 10.

The other output shaft of the drive motor 40 is connected to an encoder 48 for outputting a pulse every time the drive motor 40 rotates by a predetermined angle.

FIG. 4 shows the electrical configuration of the copying machine.

The copying machine is controlled by the CPU 50.
The CPU 50 has a ROM 51 for storing the programs and the like.
And a RAM 52 for storing necessary data. The detection signal of the position detector 15 and the output of the encoder 48 are input to the CPU 50 via an interface (not shown). From the CPU 50, the drive motor 40
A control signal is input to the drive control circuit 53 and the registration clutch 54 via an interface (not shown).

A curve Q1 in FIG. 5 indicates a first optical system traveling body 10 when the copy magnification is the reduction magnification and the continuous copy mode is set.
The curve Q2 shows the operation of the first optical system traveling body 10 when the copy magnification is the same and the continuous copy mode is used. FIG. 6 shows the first optical system traveling body 10.
3 shows the forward movement start position and the forward movement speed near the forward movement start position.

5 and 6, P1 is the first traveling start position of the first optical system traveling body 10, P2 is the second traveling starting position of the first optical system traveling body 10, P3 is the original scanning start point position, and P4 Is a document scanning end point position, and P5 is a return position. The first optical system traveling body 10 is always located at the first traveling start position. The distance between the first travel start position P1 and the document scanning start point position P2 is a magnification at which the acceleration distance of the first optical system traveling body 10 is the longest. In this example, the previous travel distance required for the reduction magnification is considered. Is set.

(1) When the copy magnification is a reduction magnification.

When the copy magnification is the reduction magnification, the first
The optical system traveling body 10 is started by the drive motor 40 from the first traveling start position P1, and as shown by the curve S1 in FIG. 6, before reaching the document scanning start position P3, the set speed V1 is reached.
And moves forward at the set speed V1 to near the return position P5. Then, the rotation direction of the drive motor 40 is switched at the return position P5, and the first optical system traveling body 10 moves backward to the first traveling start position P1 and stops.

The original image is exposed and scanned while the first optical system traveling body 10 moves between the original scanning start point position P3 and the original scanning end point position P4.

In the continuous copy mode, the forward movement of the first optical system traveling body 10 is started again, and the first optical system traveling body 10 is moved from the first traveling start position P1 to the return position P5 by the number of times corresponding to the set number of sheets. Reciprocating between As described above, when the copy magnification is the reduction magnification, the first optical system traveling body 10
Is the distance L1 between the first traveling start position P1 and the document scanning start point position P3.

The operating position (timing) of the registration clutch 54 and the stop position for returning the first optical system traveling body 10 to the return position are determined, for example, by a position detector provided at a predetermined position on the movement path of the detection plate 14. It is detected based on the detection signal. The operation position of the registration clutch 54 and the first optical system traveling body 10 are returned to the return position P.
The stop position for returning at step 5 is detected by counting the output pulses of the encoder 48 from the time when the position detector 15 stops detecting the detection plate 14 in the forward movement of the first optical system traveling body 10. You may.

The detection of the arrival of the first optical system traveling body 10 that has returned from the return position P5 to the first traveling start position P1 is determined during the backward movement of the first optical system traveling body 10.
This is performed by counting the output pulses of the encoder 48 from the time when the detection plate 14 is detected by the position detector 15.

(2) When the copy magnification is 1: 1.

The operation of the first optical system traveling body 10 when the copy magnification is the same magnification and in the single copy mode is the operation of the first optical system traveling body 10 when the copy magnification is the reduction magnification and the single copy mode. Operation is the same.

The operation of the first optical system traveling body 10 when the copy magnification is the same and the continuous copy mode is performed is as follows. That is, at the time of the first copy operation, the first
The optical system traveling body 10 is started from the first traveling start position P1 by the drive motor 40, and as shown by the curve S2 in FIG.
And moves forward to near the return position P5 at the set speed V2. Then, the rotation direction of the drive motor 40 is switched at the return position P5, and the first optical system traveling body 10 moves backward.

The original image is exposed and scanned while the first optical system traveling body 10 moves between the original scanning start point position P3 and the original scanning end point position P4.

When the first optical system traveling body 10 is in the return position P5
When the return movement is started from and the vehicle returns to the second traveling start position P2, the detection plate 14 is detected by the position detector 15.

When the detection plate 14 is detected by the second traveling start position detector 15, the rotation direction of the drive motor 40 is switched, and the first optical system traveling body 10 moves forward again. That is, at the time of the second copy operation, the first optical system traveling body 10 starts moving forward from the second traveling start position P2 and reaches the document scanning start point P3, as shown by the curve S3 in FIG. The speed reaches the set speed V2 before, and moves forward at the set speed V2 to near the return position P5.

After the first optical system traveling body 10 moves forward to the return position P5, the first optical system traveling body 10 moves backward by switching the rotation direction of the drive motor 40, and returns to the second traveling start position P2. Then, the forward movement is started again.

As described above, during the copying operation for the second and subsequent sheets, the first optical system traveling body 10 reciprocates between the second traveling start position P2 and the return position P5.

When the first optical system traveling body 10 has returned to the second traveling start position P2 during the copying operation of the last number of sheets set, the position detector 15 detects the detection plate 14. At this point, the first optical system traveling body 10 is stopped after being moved forward to the first traveling start position P1 without stopping the driving motor 50. First optical system traveling body 1
The detection that 0 has reached the first travel start position P1 is performed by counting the output pulses of the encoder 48 from the time when the position detector 15 detects the detection plate 14.

The operation of the first optical system traveling body 10 when the copy magnification is the enlargement magnification is the same as that in the case of the same magnification except that the set speed is different, and the description thereof is omitted.

That is, when the copy magnification is equal to or greater than 1 and the continuous copy mode is set, the travel start position of the first optical system traveling body 10 for the second and subsequent sheets becomes the second travel start position P2, and The distance of the preceding traveling section of the one optical system traveling body 10 is a distance L2 between the second traveling start position P2 and the document scanning start point position P3. Therefore, in the case where the copy magnification is equal to or greater than the same magnification and in the continuous copy mode, the distance becomes shorter than the distance L1 of the preceding traveling section of the first optical system traveling body 10 when the copy magnification is the reduction magnification, and the copy time is reduced. You.

In the above embodiment, the distance between the preceding traveling section of the first and second optical system traveling bodies 10 in the continuous copy mode is determined based on whether the copying magnification is the reduction magnification or the copying magnification is equal to or greater than the same magnification. Two types are set. In the continuous copy mode, the distance of the preceding traveling section of the second and subsequent first optical system traveling bodies 10 is further divided in accordance with the copy magnification so that the distance becomes shorter as the copy magnification becomes larger. May be set.

[0042]

According to the present invention, the copying time can be reduced during the continuous copying operation.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a main part of a copying machine showing an embodiment of the present invention.

FIG. 2 is a partially enlarged front view showing a detection plate and a second traveling start position detector.

FIG. 3 is an enlarged perspective view showing a driving mechanism of first and second optical system traveling bodies.

FIG. 4 is an electric block diagram showing an electric configuration of the copying machine.

FIG. 5 is an explanatory diagram for explaining an operation of a first optical system traveling body in a continuous copy mode.

FIG. 6 is a time chart showing a forward movement start position and a forward movement speed of the first optical system traveling body.

[Explanation of symbols]

 Reference Signs List 10 First optical system traveling body 11 Exposure lamp 40 Drive motor 50 CPU 51 ROM 52 RAM 53 Motor drive control circuit

Continuation of the front page (72) Inventor Hidekazu Sakagami 1-2-2, Tamazo, Chuo-ku, Osaka-shi, Osaka Mita Kogyo Co., Ltd. (56) References JP-A-59-48748 (JP, A) JP-A-63- 313176 (JP, A)

Claims (1)

(57) [Claims] 1. An image forming apparatus comprising: an optical system traveling body having an optical system for exposing and scanning an original image; and a traveling body driving device for reciprocatingly driving the optical system traveling body at a speed corresponding to a copy magnification. In the apparatus, a magnification greater than a predetermined first magnification
When performing continuous copying at the same rate, the optical system
When the running start position of the line is copied at the first magnification
Closer to the original scanning start position than the
Thus, an image forming apparatus characterized by controlling a traveling body drive device.